/**
 * input-output
 * 数据的输入与输出
 * 同步/异步
 */

const  {readFile} = require('fs');
const EventEmitter = require('events');

class EE extends EventEmitter{}

const yy = new EE();

const process = new Promise((resolve, reject)=>{

});

setTimeout(()=>{
    console.log(0)
},0);

setTimeout(()=>{
    console.log(1)
},200);

setTimeout(()=>{
    console.log(2)
},1000);

setImmediate(()=>{
 console.log('立即执行回调')
});
